To drive a plurality of loads, the conventional load driving apparatus is usually configured with a switch or a multiplexer between the output terminal of the load driving apparatus and the loads to select the load to be driven. Taking an operational amplifier as an example, FIG. 1 is a schematic diagram illustrating a conventional operational amplifier for driving a plurality of loads. Referring to FIG. 1, an operational amplifier includes a single output stage 110 and an internal circuit 120 excluding the output stage 110. A driving ability of a driving signal provided by the internal circuit 120 is enhanced by the output stage 110 and then output to the load to be driven. The output stage 110 is capable of outputting a current to a back-end load for supplying current or voltage. Therefore, to select the load to be driven, switches SW1 and SW2 are respectively configured to connect between loads 10 and 20 and the output stage 110 in FIG. 1. The switches SW1 and SW2 allow the driving signal to select one of the paths to drive the load 10 or 20.
However, since the switches SW1 and SW2 are equivalent to equivalent resistors configured on the driving path when the switches SW1 and SW2 are conducted, the driving ability of the driving signal is reduced before the driving signal is transmitted to the back-end load due to the equivalent resistor. In addition, due to configuration of the switches SW1 and SW2, the driving signal may not drive the load 10 or load 20 with a precise voltage value.